[clang] [libunwind] [llvm] [wasm] Toolchain support for `wasm32-wali-linux-musl` target (PR #156087)

[Arjun Ramesh via llvm-commits]

arjunr2 wrote:

Removing changes from the linker to a separate RT leaves pretty much primarily front-end changes.

WALI, as per the research paper and Rust, (currently) virtualizes the 64-bit Linux syscall interfaces across many ISAs. It requires 64-bit long to adhere to the Host-ABIs (i.e. x86-64, arm64, and riscv64). In the long term, there may exist another intrefaces specifically for 32-bit Linux platforms or a compatibility layer over this to accomplish the same.   

https://github.com/llvm/llvm-project/pull/156087